For many years one of the most popular games of chance has been Bingo, and commercial Bingo parlors flourish throughout the U.S. and Canada. In its simplest form, and as originally played under the name "Lotto," each participant is provided with a card printed with a square crosshatched into individual smaller squares, each of the smaller squares (with the possible exception of the center one) being permanently imprinted with a number of one or two digits. The operator of the game then randomly selects numbered discs from a container and calls out the number. Most modern Bingo parlors employ numbered balls or even computer-generated numbers. In any event, each player having a called number then places on the appropriate square a disc, marker, kernel of corn, etc., the game ending when one player has covered five squares in a line. (As a point of interest "bingo" is thought to be a corruption of "beano," referring to the use of beans as markers.) Although such cards can be reused in subsequent games, the markers tend to fall on the floor, where they are lost or stepped on, sometimes to the injury of the person doing so, and in any event contribute to the general clutter.
In recent years, Bingo has become increasingly more sophisticated, involving, e.g., including the provision of cards that no longer necessarily contain the traditional 25 small squares. For example, some of the modified Bingo cards may contain a rectangle subdivided into 25 or more smaller rectangles, of which at least 5 (but not necessarily all) are imprinted with one- or two-digit numbers. With such cards, the game winner is the first player to have five numbers called (whether or not the rectangles containing the numbers are in a line).
It is fairly common practice in Bingo parlors today to provide players with a sheet of newsprint that has been imprinted with perhaps six individual Bingo grids. Players are provided with daubers containing colored water-soluble ink, which they then apply to numbers that are announced by the game operator. Although this system is simple, convenient, and perhaps twice as fast as placing markers on the squares, the hands and clothing of the players, as well as the tables upon which they play, often become soiled with the colored ink. Further, although newsprint is comparatively inexpensive, the amount consumed in a session of Bingo is astonishingly high, and, since the sheets can be used only once, cost is a significant factor in reducing the game operator's profit.
Recognizing the expense involved in providing great quantities of newsprint sheets, attempts have been made to develop reusable equipment; thus, for example, U.S. Pat. No. 4,165,878 discloses a pocketlike game board imprinted on one side with the traditional Bingo grid of 25 squares, each individual square (other than the center one) bearing a number and having an opening. Sheets of paper are inserted into the pocket and placed at various locations, each location providing for a single game of Bingo as the player places a mark on the paper through the opening adjacent each called number. Such a device tends to be expensive, inconvenient for the average player to use, and limited to a single set of numbers.
Other attempts to make reusable Bingo cards have involved applying a glossy surface to the front of the card and placing marks with grease pencils. Although each card can then be used several times, it is inconvenient to clean, and, as in the case of the dye dauber, players often find their hands and clothing smudged.